A wireless internet connection that stops working is most likely the result of range problems or interference, but even wired internet connections can fail. If your wired internet connection regularly fails, and particularly if it tends to
do so during periods of bad weather, there could be a problem with your telephone line.

Contact your internet service provider, as it may be necessary for a telephone engineer to assess the state of the line and determine what steps should be taken. It is also possible that your ISP may be experiencing problems with its own equipment. A call to support will reveal whether this is the case, and it should only be a matter of time before the problem is solved.